反应详情

5 mL of bromine solution (2.4 g, 1.5×10-2 mole) in 20 mL of carbon tetrachloride was added to a solution of p-tolylboronic acid (2.0 g, 1.47×10-2 mole) in 40 mL of carbon tetrachloride. The reaction was initiated by illumination with a 150 Watt light bulb. The bromine color faded in 5 minutes and the remaining bromine solution was added over 15 minutes. A solid product precipitated during bromine addition. The solid was filtered and crystallized from chloroform. Yield 1.5 g (49%), m.p. 154°-156° C., 1HNMR (DMSO) δ4.18(s,2H,--CH2Br); 7.37 and 7.74(d,4H,--ArH).

1. customA solid product precipitated during bromine addition
2. filtrationThe solid was filtered
3. customcrystallized from chloroform